Field effect on planar devices made of epitaxial manganite perovskites

Abstract

Planar side gate devices are fabricated with epitaxial perovskite oxides by means of the voltage biased tip of an atomic force microscope. The high performance of the insulating gate barriers as well as the high dielectric permittivity of the chosen substrate are exploited to obtain a remarkable value of accumulated/depleted charge. We fabricate field effect devices having a ${\mathrm{La}}_{\text{0.67}}{\mathrm{Ba}}_{\text{0.33}}{\mathrm{MnO}}_3$ channel on a ${\mathrm{SrTiO}}_3$ substrate. By applying a gate voltage of +/−60 V we observe a modulation of the manganite channel resistance up to 150% at low temperatures. Furthermore, a field effect induced reversible shift by 3.2 K of the metal-insulator transition temperature is observed. This technology for prototype devices based on epitaxial oxides opens perspectives in oxide electronics applications.